參數(shù)資料
型號(hào)： LT3682IDD#TRPBF
廠商： LINEAR TECHNOLOGY CORP
元件分類： 穩(wěn)壓器
英文描述： SWITCHING REGULATOR, PDSO12
封裝： 3 X 3 MM, LEAD FREE, PLASTIC, DFN-12
文件頁(yè)數(shù)： 3/24頁(yè)
文件大?。?/td> 253K
代理商： LT3682IDD#TRPBF
LT3682
11
3682f
FB Resistor Network
The output voltage is programmed with a resistor divider
between the output and the FB pin. Choose the resistor
values according to:
RR
V
OUT
12
0 8
1
=
.
Reference designators refer to the Block Diagram. 1%
resistors are recommended to maintain output voltage
accuracy.
Setting the Switching Frequency
The LT3682 uses a constant frequency PWM architecture
that can be programmed to switch from 250kHz to 2.2MHz
by using a resistor tied from the RT pin to ground. A table
showing the necessary RT value for a desired switching
frequency is in Figure 1.
SWITCHING FREQUENCY (MHz)
RT VALUE (kΩ)
0.25
158
0.3
127
0.4
90.9
0.5
71.5
0.6
57.6
0.7
47.5
0.8
40.2
0.9
34
1.0
29.4
1.2
22.6
1.4
18.2
1.6
14.7
1.8
12.1
2.0
9.76
2.2
8.06
Figure 1. Switching Frequency vs. RT Value
Operating Frequency Tradeoffs
Selection of the operating frequency is a tradeoff between
efciency, component size, minimum dropout voltage, and
maximum input voltage. The advantage of high frequency
operation is that smaller inductor and capacitor values may
be used. The disadvantages are lower efciency, lower
maximum input voltage, and higher dropout voltage. The
highest acceptable switching frequency (fSW(MAX)) for a
given application can be calculated as follows:
f
VV
tV
V
SW MAX
OUT
D
ON MIN
IN
SW
D
()
()()
=
+
where VIN is the typical input voltage, VOUT is the output
voltage, VD is the catch diode drop (~0.5V) and VSW is the
internal switch drop (~0.5V at max load). This equation
shows that slower switching frequency is necessary to
safely accommodate high VIN/VOUT ratio. Also, as shown
in the Input Voltage Range section, lower frequency allows
a lower dropout voltage. Input voltage range depends on
the switching frequency because the LT3682 switch has
nite minimum on and off times. An internal timer forces
the switch to be off for at least tOFF(MIN) per cycle; This
timer has a maximum value of 210ns over temp. On the
other hand, delays associated with turning off the power
switch dictate the minimum on time tON(MIN) before the
switch can be turned off; tON(MIN) has a maximum value
of 150ns over temp. The minimum and maximum duty
cycles that can be achieved taking minimum on and off
times into account are:
DC
f
t
DC
f
t
MIN
SW ON MIN
MAX
SW OFF MIN
=
()
1
where fSW is the switching frequency, the tON(MIN) is the
minimum switch on time (150ns), and the tOFF(MIN) is the
minimum switch off time (210ns). These equations show
that duty cycle range increases when switching frequency
is decreased.
Agoodchoiceofswitchingfrequencyshouldallowadequate
input voltage range (see Input Voltage Range section) and
keep the inductor and capacitor values small.
Input Voltage Range
The minimum input voltage is determined by either the
LT3682’s minimum operating voltage of ~3.6V (VBD > 3V)
or by its maximum duty cycle (see equation in Operating
APPLICATIONS INFORMATION
相關(guān)PDF資料
PDF描述
LT3682EDD#TRPBF SWITCHING REGULATOR, PDSO12
LT3682EDD#PBF SWITCHING REGULATOR, PDSO12
LT5554IUH#TRPBF SPECIALTY ANALOG CIRCUIT, PQCC32
LT5554IUH#PBF SPECIALTY ANALOG CIRCUIT, PQCC32
LTC1421-2.5CSW#PBF 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO24
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LT3684 制造商:LINER 制造商全稱:Linear Technology 功能描述:36V, 2A, 2.8MHz Step-Down Switching Regulator
LT3684EDD 制造商:LINER 制造商全稱:Linear Technology 功能描述:36V, 2A, 2.8MHz Step-Down Switching Regulator
LT3684EDD#PBF 功能描述:IC REG BUCK ADJ 2A 10DFN RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 開關(guān)穩(wěn)壓器 系列:- 標(biāo)準(zhǔn)包裝:250 系列:- 類型:降壓（降壓） 輸出類型:固定 輸出數(shù):1 輸出電壓:1.2V 輸入電壓:2.05 V ~ 6 V PWM 型:電壓模式 頻率 - 開關(guān):2MHz 電流 - 輸出:500mA 同步整流器:是 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:6-UFDFN 包裝:帶卷 (TR) 供應(yīng)商設(shè)備封裝:6-SON（1.45x1） 產(chǎn)品目錄頁(yè)面:1032 (CN2011-ZH PDF) 其它名稱:296-25628-2
LT3684EDD#PBF 制造商:Linear Technology 功能描述:DC-DC CONVERTER BUCK 2.8MHZ 制造商:Linear Technology 功能描述:DC-DC CONVERTER, BUCK, 2.8MHZ, DFN-10
LT3684EDD#TRPBF 功能描述:IC REG BUCK ADJ 2A 10DFN RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 開關(guān)穩(wěn)壓器 系列:- 標(biāo)準(zhǔn)包裝:2,500 系列:- 類型:降壓（降壓） 輸出類型:固定 輸出數(shù):1 輸出電壓:1.2V，1.5V，1.8V，2.5V 輸入電壓:2.7 V ~ 20 V PWM 型:- 頻率 - 開關(guān):- 電流 - 輸出:50mA 同步整流器:是 工作溫度:-40°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:10-TFSOP，10-MSOP（0.118"，3.00mm 寬）裸露焊盤 包裝:帶卷 (TR) 供應(yīng)商設(shè)備封裝:10-MSOP 裸露焊盤
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*